This invention relates generally to a method and apparatus for locating underground objects during a digging operation and, more particularly, to a method and apparatus for determining the location of underground objects with an improved level of confidence during digging.
Earthworking machines, such as backhoes and excavators, are used to dig the earth. During the digging process, it is critical to avoid contact with underground objects such as pipes and lines. However, it is difficult, if not impossible, to know the exact locations of underground objects, and thus digging is slowed down substantially as the digging implement approaches what is believed to be the approximate location of the object to be avoided.
Advances in technologies, such as ground penetrating radar (GPR), have allowed earthworking operators some degree of confidence in determining the locations of underground objects. However, GPR cannot be used to determine the locations of underground objects with accuracy, due to variable propagation characteristics of the soil, and also due to the inherent two dimensional characteristics of the GPR signals.
The present invention is directed to overcoming one or more of the problems as set forth above.
In one aspect of the present invention a method for determining a location of an underground object during a digging operation is disclosed. The method includes the steps of delivering a signal toward the underground object, receiving a reflected signal from the underground object, determining an initial location of the underground object, creating a region of uncertainty around the underground object as a function of a level of confidence of the determined initial location, performing at least one process to improve the level of confidence, and adjusting the region of uncertainty as a function of the improved level of confidence.
In another aspect of the present invention an apparatus for determining a location of an underground object during a digging operation is disclosed. The apparatus includes means for delivering a signal toward the underground object and for receiving a corresponding reflected signal from the underground object, and a controller adapted to determine an initial location of the underground object, create a region of uncertainty around the underground object as a function of a level of confidence of the determined initial location, perform at least one process to improve the level of confidence, and adjust the region of uncertainty as a function of the improved level of confidence.